i will be building the Velleman mk103 and Canakits ck457 sound to light kits. they both use electret mics and 9v power, but are able to run off of a 12v wallwart. they have a pot for sensitivity adjustment as well.

what i want to do is this;
1. place the mic and leds on a small circuit board and mount it inside of each of my 7 drums, so that each drum only lights up when it it struck, with no "crosstalk". i would run a shielded cable for the mic and a small set of wires for the leds out through the air vent of the drum to the main circuit boards which would be mounted in a case and placed on the floor near the drumkit.
can an electret mic be distanced from the main circuit board by a 10 ft(3m) cable? i understand they require voltage to operate.
would this type of mic be too sensitve for this application? if so, how could i go about replacing it with a piezo transducer insulated with foam and secured inside the drum?

2. increase the leds to 8 for each drum. i don't think this is hard as the kits are already multi led. i would just pair up the leds if they are wired in series. i would use 3500mcd @2v, 20ma

has anyone seen someting similar to this, i don't need a blinding light show, just want a nice light from each drum as it's played. (different colored leds of course)

3. also must be low voltage, as the sound guys get nervous when you start playing around with line voltage onstage in an unapproved device.

any help would be greatly appreciated by this noob with a very limited knowledge of electronics.

1) There is no problem using 3 meters of cable with an electret mic in such an application provided the wire is shielded; what I think is more difficult is avoid crosstalking; you should lower maybe the gain of the overall circuit but I believe the drums will saturate the electret mic causing *maybe* difficulties eliminating crosstalk

Probably an accelerometer can be better suited.

In principle this task is possible to do but I'm not sure if you find something suited without building from scratch.

You can try... perhaps you have better luck with a dynamic microphone less prone to saturating;
can you try some configurations without much hassle? or you have to "go for sure"?

Or consider mounting triggers on your drums and use their signal to fire the lights. Triggers are generally piezo sensors, and are the sort of thing used with electronic drum kits. MAke your own, or buy commercial triggers. MAke one and try it.